As technologies evolve, touch tablets are developed in the market. Touch tablets have light and thin shapes, similar to the designs of liquid crystal displays. In addition, the displays of touch tablets are touch screens, allowing operations by input commands given thereon. When a user operates a touch tablet and needs to input text or symbols, the touch screen of the touch tablet shows a software keyboard emulating a physical keyboard device. The user can touch the icons on the software keyboard for inputting the corresponding text or symbols. As a consequence, text or symbols can be input to a touch tablet directly without the need of connecting to a keyboard device.
Although touch tablets have the advantages of compact size, requiring no external keyboard device, and ease of portability, users of general personal computers or notebook computers are still unable to adapt to inputting text or symbols using touch screens. Thereby, many users will prepare an additional external keyboard device connected to their touch tablets and place touch tablets on supporting objects such as bookstands for supporting touch tablets. That is to say, the touch screen of a touch tablet is used as a general display, and the external keyboard device is used for inputting text or symbols. Besides, the external keyboard device can be connected to the touch tablet via a universal serial bus (USB) or be connected wirelessly to the touch tablet via a wireless transmission module.
Moreover, there are touch notebook computers integrating a touch tablet and a keyboard device currently. Although the touch tablet is detachable from the keyboard device, it is difficult to disassemble the touch tablet from the keyboard device.